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Dean Chapman

Research involves

Using synchrotron radiation to develop new methods of x-ray imaging based on mechanisms other than absorption and applying these new methods to medical problems for both research and possible clinical application.

Research relevance

The research allows visualization of tissue in ways not previously possible with x-rays and involves the translation of synchrotron methods to clinical systems.

X-ray Vision—A Clearer View

X-rays have so much more to tell us than they are presently being asked to do. It is the hope of Canada Research Chair Dr. Dean Chapman that his research will divine the full extent of their "knowledge."

One of the most vexing problems of conventional radiography is that of scatter. In many imaging systems, over half of the detected x-rays are of scatter origin, which degrades the image contrast. Much research attention has been focused on trying to eliminate these x-rays from the system. The scattered x-rays, however, can be useful in identifying some tissue types, even cancer, and thus are of diagnostic value.

Dr. Chapman believes that all x-rays should be detected and properly interpreted and the system he is building and testing at the synchrotron is designed to do just that. The system uses diffraction enhanced x-ray imaging (DEI), a relatively new technology that makes use of x-ray refraction and scattering as well as absorption to visualize tissues in unprecedented clarity and detail. Cancers can be seen with better clarity with this imaging technique while delivering x-ray doses that are less that 3 percent of what is delivered by present radiography. Experiments have shown that it can develop image contrast 33 times higher than can conventional mammography!

One of the pioneers in the use of DEI, Dr. Chapman is perfecting this imaging method by merging it with the ability to detect and interpret scatter as the beam traverses specimens. The result is a more complete picture of the specimens, one that has many types of contrast or colours.